Tabular silver halide grains, their preparation and use in photographic emulsions, are widely known. They have been extensively studied in the literature since photographic emulsions containing these grains appeared to offer some significant advantages over photographic emulsions containing round or globular grains (e.g., splash prepared types). Generally, tabular grains are large, flat silver halide grains that are prepared by employing long ripening times or by balanced double jet (BDJ) precipitation methods. Commercial emulsions using tabular grains are conventionally made by using a BDJ process. The tabular grains usually have triangular parallel crystal faces each of which is usually larger than any other crystal face of the grain and are conventionally defined by their aspect ratio (AR) which is the ratio of the diameter of the grain to the thickness. Larger AR grains, e.g., at least 8:1, have diameters of at least 0.6 .mu.m and thicknesses of less than 0.3 .mu.m. These larger tabular grains have certain commercial advantages apparent to those of normal skill in the art. For example, they have a larger surface area and thus can accept more sensitizing dye. Since these tabular grains usually are dye sensitized, when emulsions using such tabular grains are present in medical x-ray elements an increase in sharpness can result. In addition, since the tabular grains normally lie flat when coated from an emulsion on a support, the covering power is usually greater and thus the emulsion can be coated at a lower coating weight and is therefore less costly. It is desired to prepare photographic emulsions containing tabular grains exhibiting high speed.